As is well known to those skilled in the art, it is difficult to satisfactorily cool hot gases, typically at temperatures as high as 1200.degree. F. or higher and particularly so when these gases contain particulates including ash and char. Typical of such gases may be a synthesis gas prepared as by incomplete combustion of a liquid or gaseous hydrocarbon charge or a solid carbonaceous charge. The principal desired gas phase components of such a mixture may include carbon monoxide and hydrogen; and other gas phase components may be present including nitrogen, carbon dioxide, and inert gases. The synthesis gas so prepared is commonly found to include non-gaseous (usually solid) components including those identified as ash, which is predominantly inorganic, and char which is predominantly organic in nature and includes carbon.
A particularly severe problem arises if the solids content of the gas is not lowered. Synthesis gases as produced may (depending on the charge from which they are prepared) typically contain 4 pounds of solids per 1000 cubic feed (NTP) of dry gas. These solids may deposit and plug the apparatus if they are not removed.
It has heretofore been found to be difficult to remove small particles of solids including ash, slag, and/or char from synthesis gases. These particles, typically of particle size of as small as 5 microns or less have been found to agglomerate (in the presence of water-soluble components which serve as an interparticle binder) into agglomerates which may typically contain about 1 w % of these water-soluble components. These agglomerates deposit at random locations in the apparatus typified by narrow openings in or leading to narrow conduits, exits, etc., and unless some corrective action is taken to prevent build-up, may plug the apparatus to a point at which it is necessary to shut down after an undesirably short operation period.
It is an object of this invention to provide a process and apparatus for cooling hot gases and for minimizing plugging of lines. Other objects will be apparent to those skilled in the art.